The sharp pointed blades and knives used on various agricultural implements for penetrating and parting the soil during planting, cultivating and tilling undergo severe wear as the soil impacts and abrades the metallic surfaces of the tools. To counteract abrasion and extend the life of such tools, several measures have been adapted.
In one type of construction, a coating or layer of very hard metal is adhered by welding or the like to the leading edge and perhaps one or more wear surfaces of the tool. This technique, termed hard facing, extends the effective service life of the tool due to the enhanced resistance to abrasion.
In another method, a protective part is cast from a high density, high hardness metal, such as chromium carbide. This part is then welded to the leading edge or forward point of the blade, or the shank to be protected against abrasion, in a position to take the impact and abrading action of the soil, and to deflect the soil away from the softer steel of which the blade or shank is constructed. This type of assembly is typified by the structures shown in U.S. Pat. No. 4,355,589.